Electric melting or reducing furnace.



PATENTED JAN. 22, 1907. G. C. LANDIS.

ELECTRIC MELTING 0R. REDUCING PURN ACE.

APPLICATION FILED SEPT.21,1904.

2 SHEETS-SHEET 1. k t p No. 842,099. PATENTED JAN. 22, 1907.

. G. G. LANDIS. ELECTRIC MELTING 0R REDUCING FURNACE.

APPLIOATION FILED SEPT. 21.1904.

2 SHEETSSHBET 2.

UNITED STATES PATENT OFFICE.

GILBERT (J. LANDIS, OF (JARLISLE, PENNSYLVANIA, ASSIGNOR TO AMERICAN PHOSPHOROUS COMPANY. OF CAMDEN, NEW JER- SEY, A CORPORATION OF NEW JERSEY.

ELECTRIC MELTING OR REDUCING FURNACE.

Specification of Letters Patent.

Patented J an.- 22, .1 907.

Application filed September 21, 1904. Serial No. 225.361.

To all whom it may concern:

Be it known that I, GILBERT C. LANDIS, a

citizen of the United States, residing at Carlisle, Pennsylvania, have invented certain Improvements in Electric Melting or Reducing Furnaces, of which .the following is a specification.

The objects of my invention are to soconstruct the furnace as to prevent fumes, vapors, or gases from escaping therefrom or from'beingabsorbed by the furnace-lining, to permit ready adjustment of the carbon electrode of the-furnace, and to simplify and cheapen the repair or replacement of those portions of the furnace which are subject to wear.' These objects I attain in the mannersection, on the line 2 2, Fig. 1. Fig. 3 is a.

view similar to Fig. 2, but illustrating the use of a plurality of carbon electrodes and the electrical connections therefor ;v and Fig. 4 is an enlarged section of a portion of the furnace.

The metallic casing Bof the furnace is preferably of rectangular shape and contains ing A a lining A, the latter being composed of vitrified or other non-absorbent bricks or blocks united by a non-absorbent mortar or cement such, for instance, as one composed of silicate of soda and powdered asbestos. Within this outer non-absorbent lining A of the fprnac-c is a lining E, composed of bricks or blocks of carbon or other heat-resisting and electric conducting material, and this conductinglining is preferably composed of an inner set of blocks as and an oute1 set of blocks 0;, so that when in the operation of the furnace the inner blocks becomeworn away they can be replaced witnout disturbing the outer blocks as, the relining of the furnace being thereby efi'ected more cheaply than if the entire carbon lining had to be removed. The p ose of constructing the outer linofi the furnace from vitrified or other non-absorbent bricks or blocks laid in a nonabsorbent mortar or cement is to prevent the absorption by said outer lining of gases,

fumes, or vapors generated during the action of the furnace, thereby preventing loss of such fumes, gases, or vapors or rendering un-, necessary the removal and subsequent treatment of the lining A for their recovery.

The carbon lining E of the furnace rests upon a base-plate C of conducting material, which has a rod 0 projectingthrough the lining A and easing B of the furnace and through a cap-plate c, suitably insulated from said casingB, said rod 0 being provided-Qwith a terminal block C to'which one of the electric conductors is suitably attached.v

The furnace has aremovable cap-plate G, which is provided at its outer edge with an upturned flange b and a downturned flange b, the upturned flange constituting the capplate a tray or vessel for the reception of water or other cooling fluid, whereby its temperature is maintained at a 'low point, the downturned flange of the plate dipping into a chamber 6 formed between the upper portion of the casing B and a flange g, which extends around said casing and is secured thereto, this chamber containing water or other suitable liquid or other sealing agent whereby the escape of any fumes from the furnace between the top of the same and the cap-plate is effectually prevented.

The cap-plate G has a central vertical pro-.

-j[ecting neck J and two inclined necks H and the neck H serving for the delivery to the treating-chamber of the furnace of the material-t0 be acted onthereby and the neck I serving for the escape of the fumes, vapors, or gases resulting from the treatment.

The neck H has an extension H with branch H upon which is mounted a hopper h for receiving the material to be treated, the bottom of this hopper being normally closed by a valve h, which is suspended by a chain h from a segment. 71 on a rock-shaft h, the latter having an operating-lever h with counterweighthiwhereby the valve b can be readily raised, so as to close the bottom of the hop- The top of the hopper h is provided with a pivote and horizontally-swinging cap or cover It.

The neck J has mounted upon it a sealing vessel K, suit ably insulated from said neck by means of an mterposed mass of non-conductwhereby it can be sus ended from or otherwise attached to a crane or other supporting and adjusting device, vertical adjustment ofthe carbon electrode F being necessary in order that its lower end may bear the proper relation to the mass of material contained in the working chamber c of the furnace, so that the load or electrical energy may be constant or so that the lower end of the electrode may be held free from contact with such material if the furnace is operating on the arc princi: ple, or can be embedded in the material if the latter is intended to be heated to incandescence by the passage of the current therethrough. Such adjustments of the carbon electrode F are, by reason of the seal K M, readily permitted without any escape of fumes, vapors, or gases from the furnace, and if, because of the wearin away of the lower end of the carbon electro e, vertical readjustment of the latter in respect to the sealingcup M becomes necessary such vertical readjustment can be readily effected without arresting the operation of the furnace by slackening the set-screws f and lowering the electrode through the cup, a luting f of fire-clay or other refractory material closing the joint between the electrode and the cup M, so as to prevent the escape of any fumes, gases, or vapors at that point. By this means I provide a simple and effective substitute for the ineffective stuffing-boxes which have sometimes been employed for forming the joint with the adjustable electrode in an electrical furnace. Stuffing-box packing applied di-. rectly to the surface of the carbon electrode is not effective because of the relatively rough and irregular surface presented by the latter, and if the carbon electrode is provided with a metal casing for the purpose of insuring a tighter joint at the stufling-box said metal is rapidly destroyed by the heat of the furnace.

The outer wall k" of the sealing vessel K has, some distance below t;:e top of the same, a projecting flange k, with vertically-projecting flange k, forminga chamberk for the re: eeption of any water or other sealing liquid which may overflow from the sealing-chamber between the walls k 7:, thereby preventing such overflow from formin a short circuit between the carbon electrode and the capplate G of the furnace.

The neck I of the cap-plate G is provided with a discharge branch I, and both necks H and I are provided with reciprocatingscrapers for the purpose of removing therefrom the products of condensation which accumulate therein, the scraper which operates in connection with the neck H H being represented at n and that which operates in connection with the neck I I being re resented at s.

The scraper n is carried y arod N, which passes through a suitable stufiingbox at the outer end of the neck H, said rod having a handle n, whereby the scraper can be readily moved up and down through the neck H H, so as to remove any accumulations therefrom and 'deliver them into the treatingchamber 6 of the furnace. The scraper s is likewise provided with a rod S, having a lian: dle 8, said rod passing through a suitable stuffingborg at the outer end of the n ck I.

The inner carbon lining w of the furnace is provided with oppositely-disposed tapping. openings 6-, provided with suitable plugs c and the outer carbon liningm is provided Wllh tapping-spouts a which are normally closed by means of plu s eof carbon or other heat-resisting materia The inner plugs e niay likewise be com osed of carbon, al: though in rac'tice it lies been found sufii: cient to ma e these plugs of wood, which are quickly carbonized by the heat of the fur. nace. By providing inner and outer tapping-openings e and e I am enabled to use a plug 6 of wood for the inner opening without lu1ing,as it is difficult of access, and I close the outer opening by the plug eflwhich is luted, preventing air reaching the inner W dBII plug.

The furnace is continuous in its operation, and the molten slag is tapped therefrom at suitable intervals. The tapping-openings are by reason of the friction of the flowing slag worn away more rapidly than the blocks of the inner carbon lining 1:. Hence the provi: sion of two sets of tappingeop'enings, so that when one set becomes wow so as to be inca: pable of further use it can be permanently plugged and the other set brought into ac.- rion until it also. becomes Worn out,bywhicli time a renewal of the inner carbon'lining x of the furnace will be necessary. The outer -lIO tapping-spouts e of the furnace are retained tangular form of the electrodes furnishing V another reason why an ordinary stuflingebox would not loo-effective for packing the joint between the same and the ca of the furnace.

In Fig. 2-, y, represents a attery or other suitable generator of electricity, one pole of which-is connected to. the-electrode F and the other to the terminal block 0 of the bases plate C, upon which rests the carbon lining of the furnace, the latter connection having a suitable switch y. Y

In the furnace shown in Fig. 3 a plurality inner portion haying a plugged tapping-opennon-conducting material, a lining of conductmetallic casing and having an opening, a tapping-spout of conducting material extending GILBERT C. LANDIS.

of electrodes Fare employed, andin this case i through said plate, and insulating material 6 the electrical connections are provided with between the plate and the casing, said matethree switches y 3 y so that if the switches i rial also insulating the spout from the casing,

'y and g are closed and the switch y is I substantially as described. opened the two electrodes constitute the 7. The combination in an electric furnace, plpsitive terminal and the carbon lining of the i of a body portion having a conducting-lining, 70 rnaceconstitutes the negative terminal, an electrode extending into the furnace, a top while if the switches y and y are opened and plate, an inclined passage therein, said pasthe switch y closed one of the electrodes consage extending through the upper portion of stitutes the positive terminal and the other the furnace and communicating with the rethe negative terminal, thus roviding for the ducing-chamber, said passage being so ar- 75 operation of, the furnace un er different conranged that a tool may be passed through the d1tions',a's may be considered most advisable. inclined passage into the reducing-chamber Having thus described my invention, I to break the arch of materialbeing treated claim, and desire to secure byLetters Patent above the bath, substantially as described.

1. The combination in an electric furnace, 8. The combination in an electric furnace, c of abody portion, a top plate, a neck proof a casing having a non-conducting lining, jecting from the topplate, an extension on an electrode vertically arranged within the saida'ieck forming one portion ofa fluid seal, furnace, a top plate secured to the body of insulating material'between the neck and the the furnace having a neck through which the extension, a movable element of said sealing electrode extends, two inclined passages ex- 5 device, means by which said element is setending through the top plate of the furnace, cared to the electrode which passes through a feed-hopper connected to one passage and a the neck into the body of the furnace, and a gas-discharge pipe communicating with the receptacle on the extension above said insuother passage, a scraper in each passage, each 1 lation for receiving the overflow of sealing scraper having a rod, and a stufling-box at the 9 fluid from the sealing device,- substantially as end of each passage through which the rod described. 7 extends, whereby the said passages can be 2; The combination in an electric urnace, cleaned and the crust over the material to be ofa body portion, a to plate having a flange treated can be broken, substantially as deso as to hold a body 0 water to cool the said scribed. 95. top plate, a neck. extending above the water- 9. The combination in an electric furnace. line, an extension on said neck through which of a body portion having a carbon lining, a the electrode passes, a seal-joint between top plate made in a single casting secured to said extension and the electrode, and insulathe said body portion, agas-tight joint be' tion between the neck and the extension tweenthe body portion and the top plate, above the water-line, substantially as desaid top plate having a central neck and two scribed. side inclined passages, a flange whereby a 3. Theco nbination in an electric furnace, body of water maybe held on the top plate, of a casing having a non-absorbent outer linan extension above the neck,1nsulat1ng mate- I 45 ing, an inner lining comprising inner and rial between the extension and the neck 5 7 outer portions both made of carbon blocks, above the water-line, a carbon extending the inner portion being removable inde end through the central passage, a sealoint beently of the outer portion, substantially as tween the carbon and the extension of the described. neck, a feed-hopper connected .with one of the 5 4. An electric furnace havinga carbon lininclined passages, the other inclined passage I 10 ing comprising inner and outer portions, being the gas-outlet, and scrapers in each each provided with a plugged tapping-openpassage, substantially as described. -ing,substantiallyasdescribed, 1 In testimony whereof I have signed my 5. An electric furnace having a carbon linname to this specification in the presence of 5 ing comprising inner and outer portions, the two subscribing witnesses.

' ing and the outer ortion having a projecting apping-Spout, sulistantially as described.

' 6. The combination in an electric furnace,

60 of a metallic casing and a body portion of l Witnesses:

WILL. A. BARR, Jos. H. KLEIN. 

